Bi-institutional spline curve analysis of lymph node mapping in gallbladder cancer operated over 12 years: Impact of location and number of lymph nodal stations.

person Shraddha Patkar Tata Memorial Hospital (HBNI), Mumbai, India info_outline Shraddha Patkar, Prabhat Ghanshyam BHARGAVA, Vikas S. Ostwal, Anant Ramaswamy, Swapnil Patel, Mahesh Goel

Authors person Shraddha Patkar Tata Memorial Hospital (HBNI), Mumbai, India info_outline Shraddha Patkar, Prabhat Ghanshyam BHARGAVA, Vikas S. Ostwal, Anant Ramaswamy, Swapnil Patel, Mahesh Goel Organizations Tata Memorial Hospital (HBNI), Mumbai, India, Tata Memorial Centre, Mumbai, India, Department of Medical Oncology, Tata Memorial Hospital, Mumbai, India, Tata Memorial Centre (HBNI), Mumbai, India, Department of Surgical Oncology, Varanasi, India, Tata Memorial Center (HBNI), Mumbai, India Abstract Disclosures Research Funding No funding sources reported Background: Current staging system for gallbladder cancers (GBC) takes into account only the number of metastatic lymph nodes without addressing their location. The current study evaluates the prognostic impact of lymph node mapping (number and location) in node positive GBCs. Methods: Prospectively maintained operative database of GBC patients with positive lymph nodes were analysed from two tertiary cancer care centers in a retrospective cohort study design between April 2010 till March 2022. Nodal burden was assessed including both, the number of metastatic nodes and the lymph node station. Impact of lymph node ratio (LNR) and log odds of positive lymph nodes (LODDS) was evaluated using regression and spline curve analysis. Results: Amongst 1312 operated GBC patients, 272 patients with node positive disease were included. The median nodal yield was 8. The median LNR and LODDS was 0.222 and -0.48 respectively. The 5-year DFS and OS for patients with only cystic node metastases was 52.3% and 50.8% respectively (median: not reached), as compared to 24.6% and 35.2% for involvement of regional nodal stations beyond cystic nodes. Higher LODDS was associated with inferior DFS and OS when compared to the LNR. On multivariate analysis, multi-station involvement was the only factor associated with inferior DFS (p < 0.001) and OS (p = 0.007). Conclusions: Station wise pathological assessment of lymph nodal involvement could potentially provide superior prognostic information, in addition to number of involved nodes. Involvement of cystic lymph node alone has relatively superior prognosis as compared to multi-station involvement.